The three dimensional organization of the 30S ribosomal subunit from E.coli will be explored using the neutron scattering, distance finding method. The conformational properties of native ribosomal subunits will be examined by X-ray scattering as a function of temperature and ionic conditions and compared to those of ribosomal RNAs. The interactions of a number of isolated ribosomal proteins with their cognate RNA binding sites will be investigated by proton NMR.